Cam drive pump refrigerators

ABSTRACT

This is a counter-bevelled cam drive piston pump with optional multiple stages of compression and vacuum pumping for use in compression pumping, vacuum pumping and open or closed cycle refrigeration.

United StatesPatent 1 [111 3,914,958

Nelson Oct. 28, 1975 CAM DRIVE PUMP REFRIGERATORS 668,540 2/1901Ostergren 62/403 Inventor: an el E. son, 661 Selkirk Dri e, 2,903,8629/1959 Bouchard 62/403 Winter Park, Fla. 32789 FOREIGN PATENTS ORAPPLICATIONS 22 i Oct. 23 1973 8l0,857 3/1959 United Kingdom 62/403 [21]Appl' 408628 Primary ExaminerWilliam E. Wayner [52] US. Cl 62/403'62/403 AB T T 51 Int. cm F2sl) 9/00 [57] S C [58] Field of Search62/401, 403, 498 This is a counter-bevelled Cam drive Piston P p withoptional multiple stages of compression and vacuum 5 References Citedpumping for use in compression pumping, vacuum UNn-ED STATES PATENTSpumping and open or closed cycle refrigeration.

255,895 4/1882 Starbuck 62/403 7 Claims, 1 Drawing Figure I I I 1 3 F 16 I 55 18 91 7) 61 3 34 4 3% 32 31] J 4 5 4 1O 11 V 14 1 2 3 3 1 7 4 22O 5 2 4 2Q) I 3 39 i 5 I l U.S. Patent Oct. 28, 1975 3,914,958

CAM DRIVE PUMP REFRIGERATORS Objects of this invention are to provide aplungertype pump with highly efficient conversion of rotary motion toreciprocating travel.

Another object of this invention is to provide the high efficiency of amultiple-staged plunger-type pump with a highly efficient means ofobtaining reciprocating travel from rotary motion in conjunction withthe advantageous sealing made possible by a piston-type pump.

Another object of this invention is to provide a multiple-staged pumpcapable of extremely high use life and low weight.

Another advantage of this invention is to provide a combinationcompressor pump and vacuum pump with extremely high efficiency, lowweight, and long use life for open or closed cycle refrigerationsystems.

Most current compressors or vacuum pumps which utilize plunger actionrequire crank-shaft-type conversion of rotary power to reciprocatingaction. The weight is approximately as much as the engine which drivesthem. The counter-bevelled cam drive compressor and vacuum pumpdescribed in this application can be made to weigh as little as five toten per cent of this proportionate amount.

High output per weight of pumps usually requires the use of turbineblades, impellers, or some form of rotary vaned or rotary piston pump.These rotary pumps sacrifice sealing efficiency or actual compressionefficiency to obtain efficient rotary motion.

This device, however, provides high output per weight in conjunctionwith high efficiency for the means of both compression and utilizingrotary motion.

This invention is illustrated in the accompanying drawing.

The operation of these improvements in pump and refrigeration systems isdescribed in the following manner. Rotational power is provided througha rotational power source 1. This power source is illustrated as abelt-driven wheel but could be any other power conveyance source orprime mover, including a centrally positioned prime mover or electricmotor with a power output shaft at both ends.

A left drive shaft 2, and a right drive shaft 3 are attached at oppositesides of the power source and extended in rotational contact throughleft and right bearings 4 and 5 in left and right housings 6 and 7respectively at opposite sides of the power source.

The drive shafts are attached to left and right drive shaft sleeves 8and 9 by means of left and right plates 10 and 11.

Left and right counter-bevelled grooves 12 and 13 are formed around theinside periphery of left and right sleeves 8 and 9 by two pairs of twoidentical counterbevelled end cams l4, 15, 16, and 17 in the sleeves.

The end cams are separated to form the counterbevelled cam drive grooves12 and 13 between them.

Left and right drive teeth 20 and 21 are extended radially into thegroove from left and right shafts 22 and 23. Transverse guides 24 and 25are rigidly attached to the housing at baseplates l8 and 19 and areprovided with channels 26 and 27 in which the radially extended driveteeth are caused to reciprocate when the power source and drive sleeveare rotated.

The reciprocating shafts are extended in slidable contact through thebaseplates 18 and 19 into compressor cylinders 30 and 31 at oppositesides of compressor piston 32 and similarly. into cylinders 33 and 34 atopposite sides of compressor piston 35.

Various modes of operation can be achieved by varying the sizesand'proportions of the components and by varying thefluid circuitry withappropriate valves and conveyance'means within the system. One such modeis a four-staged compressor.

A four-staged compressor is achieved by first constructing one side 36of one piston 35 with a larger surface area than the other side 37. Thisdifference in size can be obtained by using a larger shaft 23 on oneside than the shaft 38 on the other side. Alternatively, the shaft 38can be omitted along with the slidable contact with the outside head 39of cylinder 34.

Cylinders 30 and 31 are then constructed smaller in diameter thancylinders 33 and 34. Piston 32 is constructed proportionately smallerand side 40 is made smaller than side 41 by having shaft 22 made smallerin diameter than shaft 42 or by omitting shaft 42 and its slidablecontact through cylinder head 43.

Four-stage compressor mode utilizes inward travel of piston 35 to drawair or other fluid into cylinder 34 through conveyance 44 at port 45while valve 46 is open. The fluid is directed through conveyance 47 intosmaller cylinder 33 when valve 48 is open. The return travel of piston35 further compresses the fluid past open valve 49 into conveyance 50and then into conveyance 51 where it is directed into still smallercylinder 30 past valve 52 when piston 32 is caused to travel inwardlyfor a third stage of compression. A fourth stage of compression isachieved at side 40 of piston 32. Fluid is directed from cylinder 30through conveyance 53 and past valve 54 into cylinder 31. There it iscompressed into a final stage by the return travel of piston 32 anddirected out through conveyance 55 past valve 56 when it is open.

The variation of the piston surface areas, with their respectivecylinders, can be much greater than is illustrated for obtainingextremely high compression ratios. The use of multiple stages to achievehigh compression has the advantage of increased sealing capacity in'addition to higher pressure per surface area of plunger piston.

A two-stage compressor is achieved by terminating the above process atconveyance 51 after utilizing only piston 35 in cylinders 33 and 34.

An equal or unequal stage capacity of the doublestage compressor can beprovided at each side of the power source 1 by terminating each stage atsecond outlets55 and 50 respectively.

The device can be sin gle-staged by making both sides of the pistonswith equal surface areas through use of the same diameter shafts ateither side of the piston.

A vacuum pump can be provided by utilizing the inlet conveyance means tothe cylinders as the vacuum pump lead line.

A particularly useful mode of operation for this device is that of arefrigeration system. It can be made to utilize both the compression andthe vacuum aspects of the device simultaneously, or either separately.

Employing compression and vacuum modes in a single refrigeration systemmakes possible the use of working media gasses that are more plentifulbut are not as compressible and expandable as freon or otherrefrigerants in common use. Air, in particular, can be used in eitherclosed or open cycle refrigeration with high efficiency and low costwith this device.

Refrigeration mode, with compression and vacuum pumping employed incombination, employs a heat exchanger 56 in fluid communication betweenthe left and right cylinders or pairs of cylinders. Air or other fluidcoolant media is compressed into the heat exchanger where heat ofcompression in the fluid is transferred outside the system. The coolantmedia is then vacuum-pumped out of the heat exchanger by the oppositepump from the one which was employed to compress it.

The direction of coolant flow from left to right in the illustrationdemonstrates the practice of using a larger piston for the vacuum pumpthan for the compressor pump. The size ratio is highly exaggerated,however, just to make use of the same illustration for the refrigeratormode of operation as for the four-stage compressor mode.

The valves can be reversed for the reverse flow of fluid. Thus, there isillustrated a schematic one-way valve at the opposite side of each portfrom that called out for the four-stage compressor. These valves can besimple one-way compressor valves as common to the compressor art.

A heat exchange exit restriction 57 is used to retain pressure withinthe heat exchanger at a sufficiently high pressure ratio and to allowfor high expansion ratio in the cylinder. The restriction means can be apressure valve or an appropriately sized venturi as illustrated,depending on the application requirements.

A collector box 58 can be employed to provide constant pressure to thevacuum cylinders to compensate for fluctuation of vacuum pressure fromthe piston system.

An inlet safety valve 59 is provided to allow air, if it is used as thecoolant, to be drawn into the vacuum pump prior to possible excessivebuild-up of pressure in the heat exchanger.

The collector box can be used as a first-stage cooler for someapplications of the device. It can serve as a freezer unit while a maincooler 60 can be employed in cooling relationship to objects or areasbeing cooled.

A closed loop refrigeration system is provided by directing the expandedcoolant from the vacuum pump through conveyances 44 and 61 into aradiation tube or tubes 62 in the cooler. The coolant is thenrecirculated back through the compressor portion of the device,illustrated at the left side, through conveyances 55 and 63.

An open cycle is provided when the conveyances 44, 61, 55, and 63 arenot connected in fluid conveyance communication through conveyance 62,nor cooler between them. lnstead, conveyances 44 and 61 are extendeddirectly into the area being cooled. Conveyances 55 and 63, thecompressor inlets would be extended into the same area if recirculationfrom the cooled area is desired in open refrigeration cycle. Thecompressor inlets can also be constructed to obtain part or all of thecoolant from inside or outside of the cooled area.

Other variations of this device include construction with all pistonsurfaces substantially the same area. All four pistons can then be usedfor one compressor or for one vacuum pump or a combination of twocompressors and two vacuum pumps with or without a heat exchange unit,and with or without a cooling unit between them.

Another variation is a single phase pump utilizing just one side of thedevice illustrated. A coolant can be pumped from one side of a piston tothe other through outside tubes for refrigeration cycle in this mode. Acooler could be used for closed cycle or an open cycle could be employedin the same working relationship as described above for the stagedcompressor and vacuum pump system. This is shown at the right side ofthe illustration by utilizing piston 35 as both a compressor and avacuum pump. The valves and channels through the piston would beremoved. The heat exchanger 56 would be in the place of the collectorbox 58. The cooler would be positioned between conveyances 44 and 61 ifa closed cycle were used. Valves at ports, restrictions and safetyvalves would be used as described above and in present art pump andrefrigeration practices.

Another variation of the device is to construct the shaft sleeves 8 and9 as one sleeve and attach the power source 1 to the outside of thesleeve. This eliminates the bearing flange section of the housing. Thetransverse guides 24 and 25 are then combined as one unit.

For greatest balance, reliability and efficiency in utilizing thecounter-bevelled cam drive as described above, it has been found best toutilize three or more drive teeth and to have the drive angle of the endcams over sixty degrees from the shaft axis.

What is claimed is:

l. A multiple-staged cam drive pump refrigerator having a housing, arotational power source, a drive shaft attached to the rotational powersource and in rotational contact with the housing, a sleeve attached tothe drive shaft, a counterbevelled cam drive groove in separated end camrelationship around the inside periphery of the sleeve, a transverseguide having channels parallel to the drive shaft and rigidly attachedto the housing, a double-ended pump cylinder rigidly attached to thehousing, a double-ended pump piston in slidable contact with the insideof the cylinder, a piston shaft attached to one side of the piston andextended in slidable contact through the cylinder head at one end of thedouble-acting cylinder, cam follower teeth extended radially from theshaft in slidable contact with the surfaces of the transverse guide andwith the surfaces of the counter-bevelled cam drive, a connecting fluidconveyance in communication between the portion of the cylinder at onehead of the piston and the portion of the cylinder at the opposite headof the piston, a fluid conveyance in communication between the insideand the outside of each end of the cylinder, pump valves that are causedto be open when the piston is traveling away from and closed when it istraveling towards the cylinder heat at the conveyance between the insideand the outside of the cylinder at intake end of the cylinder, pumpoutlet valves that are caused to be closed when the piston is travelingaway from and open when it is traveling towards the cylinder head at theconveyance between the inside and the outside of the cylinder at theoutlet end of the cylinder, connecting conveyance pump valves that arecaused to be closed when the piston is traveling away from and open whenit is traveling towards the cylinder head at the intake end of thecylinder, connecting conveyance pump valves that are caused to be openwhen the piston is traveling away from and closed when it is travelingtowards the cylinder heat at the outlet end of the cylinder, and a heatexchanger at the connecting fluid conveyance between the intake andoutlet ends of the cylinder.

2. A multiple-staged cam drive pump refrigerator as described in claim 1and having a heat exchanger at the connecting conveyance means betweenthe intake and outlet ends of the cylinder, and a cooler in fluidcommunication between the intake and outlet ends of the cylinder.

3. A multiple-staged cam drive pump refrigerator as described in claim 1and having a heat exchanger at the connecting fluid conveyance meansbetween the intake and outlet ends of the cylinder, and a fluid-flowrestriction at the outlet end of the heat exchanger upstream of thefluid conveyance into the outlet end of the cylinder.

4. A multiple-staged cam drive pump refrigerator as described in claim 1and having a heat exchanger at the connecting fluid conveyance betweenthe intake and outlet ends of the cylinder, a fluid restriction at theoutlet end of the heat exchanger upstream of entry of the fluid into theoutlet end of the cylinder, a collector box in fluid communicationbetween the restriction and the entry of the fluid into the outlet endof the cylinder.

5. A multiple-staged cam drive pump refrigerator having a rotationalpower source, a housing at each side of the power source, a drive shaftsleeve at each side of the power source in rotatable contact with therespective housings, counter-bevelled cam drive grooves in separated endcam relationship around the inside periphery of each sleeve, transverseguides having channels parallel to the drive shaft and rigidly attachedto each of the housings, a double-ended pump cylinder rigidly attachedto each housing, doubleended pump pistons in slidable contact with theinside a conveyance in fluid communication into the cylinder at one sideof the power source, a conveyance in fluid communication out of thecylinder at the opposite side of the power source, ports with pumpvalves in one-way working relationship into and out of the cylinder atone side of the power source upstream of entry into the conveyancebetween said cylinders at opposite sides of said power source, portswith pump valves in one-way working relationship into and out of thecylinder at the opposite side of said power source downstream from thesaid conveyance between the said cylinders at opposite sides of saidpower source, conveyances between the portions of the cylinders at theopposite sides of the pistons in each respective cylinder, ports thereatwith pump valves in one-way working relationship into and out of thesaid opposite ends of the said cylinders, and a heat exchanger at theconveyance between the cylinders that are positioned at opposite sidesof the power source.

6. A multiple-staged cam drive pump refrigerator as described in claim 5and having a heat exchanger at the conveyance between the cylinders thatare positioned at opposite sides of the power source, and a cooler influid communication between the opposite inlet and outlet conveyances tothose which are in fluid communication with the heat exchanger betweensaid cylinders.

7. A multiple-staged pump refrigerator as described in claim 5 andhaving a heat exchanger at the conveyance between the cylinders that arepositioned at opposite sides of the power source, a coller in fluidcommunication between the opposite inlet and outlet conveyances to thosewhich are in fluid communication with the heat exchanger between saidcylinders, and a fluid flow restrictor at the outlet end of the heatexchanger. l

1. A multiple-staged cam drive pump refrigerator having a housing, arotationAl power source, a drive shaft attached to the rotational powersource and in rotational contact with the housing, a sleeve attached tothe drive shaft, a counterbevelled cam drive groove in separated end camrelationship around the inside periphery of the sleeve, a transverseguide having channels parallel to the drive shaft and rigidly attachedto the housing, a double-ended pump cylinder rigidly attached to thehousing, a double-ended pump piston in slidable contact with the insideof the cylinder, a piston shaft attached to one side of the piston andextended in slidable contact through the cylinder head at one end of thedouble-acting cylinder, cam follower teeth extended radially from theshaft in slidable contact with the surfaces of the transverse guide andwith the surfaces of the counter-bevelled cam drive, a connecting fluidconveyance in communication between the portion of the cylinder at onehead of the piston and the portion of the cylinder at the opposite headof the piston, a fluid conveyance in communication between the insideand the outside of each end of the cylinder, pump valves that are causedto be open when the piston is traveling away from and closed when it istraveling towards the cylinder heat at the conveyance between the insideand the outside of the cylinder at intake end of the cylinder, pumpoutlet valves that are caused to be closed when the piston is travelingaway from and open when it is traveling towards the cylinder head at theconveyance between the inside and the outside of the cylinder at theoutlet end of the cylinder, connecting conveyance pump valves that arecaused to be closed when the piston is traveling away from and open whenit is traveling towards the cylinder head at the intake end of thecylinder, connecting conveyance pump valves that are caused to be openwhen the piston is traveling away from and closed when it is travelingtowards the cylinder heat at the outlet end of the cylinder, and a heatexchanger at the connecting fluid conveyance between the intake andoutlet ends of the cylinder.
 2. A multiple-staged cam drive pumprefrigerator as described in claim 1 and having a heat exchanger at theconnecting conveyance means between the intake and outlet ends of thecylinder, and a cooler in fluid communication between the intake andoutlet ends of the cylinder.
 3. A multiple-staged cam drive pumprefrigerator as described in claim 1 and having a heat exchanger at theconnecting fluid conveyance means between the intake and outlet ends ofthe cylinder, and a fluid-flow restriction at the outlet end of the heatexchanger upstream of the fluid conveyance into the outlet end of thecylinder.
 4. A multiple-staged cam drive pump refrigerator as describedin claim 1 and having a heat exchanger at the connecting fluidconveyance between the intake and outlet ends of the cylinder, a fluidrestriction at the outlet end of the heat exchanger upstream of entry ofthe fluid into the outlet end of the cylinder, a collector box in fluidcommunication between the restriction and the entry of the fluid intothe outlet end of the cylinder.
 5. A multiple-staged cam drive pumprefrigerator having a rotational power source, a housing at each side ofthe power source, a drive shaft sleeve at each side of the power sourcein rotatable contact with the respective housings, counter-bevelled camdrive grooves in separated end cam relationship around the insideperiphery of each sleeve, transverse guides having channels parallel tothe drive shaft and rigidly attached to each of the housings, adouble-ended pump cylinder rigidly attached to each housing,double-ended pump pistons in slidable contact with the inside of eachcylinder, conveyances in fluid communication between the cylinder at oneside of the power source and the cylinder at the other side of the powersource, a conveyance in fluid communication into the cylinder at oneside of the power source, a conveyance in fluid communication out of thecylinder at the opposite side of the Power source, ports with pumpvalves in one-way working relationship into and out of the cylinder atone side of the power source upstream of entry into the conveyancebetween said cylinders at opposite sides of said power source, portswith pump valves in one-way working relationship into and out of thecylinder at the opposite side of said power source downstream from thesaid conveyance between the said cylinders at opposite sides of saidpower source, conveyances between the portions of the cylinders at theopposite sides of the pistons in each respective cylinder, ports thereatwith pump valves in one-way working relationship into and out of thesaid opposite ends of the said cylinders, and a heat exchanger at theconveyance between the cylinders that are positioned at opposite sidesof the power source.
 6. A multiple-staged cam drive pump refrigerator asdescribed in claim 5 and having a heat exchanger at the conveyancebetween the cylinders that are positioned at opposite sides of the powersource, and a cooler in fluid communication between the opposite inletand outlet conveyances to those which are in fluid communication withthe heat exchanger between said cylinders.
 7. A multiple-staged pumprefrigerator as described in claim 5 and having a heat exchanger at theconveyance between the cylinders that are positioned at opposite sidesof the power source, a coller in fluid communication between theopposite inlet and outlet conveyances to those which are in fluidcommunication with the heat exchanger between said cylinders, and afluid flow restrictor at the outlet end of the heat exchanger.